Welding wire preheating system and method
In a welding system, a preheating process is carried out prior to initiation of a welding arc, such as upon depression of a trigger or switch on a welding torch. The preheating process involves generation and application of desired currents and voltages to a welding electrode from a power supply. Preheating is continued until the welding electrode reaches a desired temperature or resistance, which may be determined by reference to an increasing voltage, a decreasing current, a peaked and declining voltage, resistance and/or power measurements, and so forth. Following preheating, a desired welding process may begin with initiation of the welding arc.
1. A welding method, comprising:
receiving a signal indicative of initiation of welding process;
prior to initiating a welding arc based on the received signal, controlling voltage or current applied to a welding electrode to preheat the electrode to a temperature above an ambient temperature but below a melting point of the welding electrode;
monitoring feedback voltage and current to determine a termination of preheating; and
terminating preheating prior to initiating the welding arc in accordance with a welding protocol.
2. The method of claim 1 , wherein the signal is received from a welding torch as a result of an operator depressing a trigger of the torch.
3. The method of claim 1 , wherein during preheating, current applied to the welding electrode is maintained generally constant and voltage feedback from the electrode is monitored for an increase.
4. The method of claim 3 , wherein preheating is terminated when the voltage feedback from the electrode reaches a predetermined threshold value.
5. The method of claim 3 , wherein preheating is terminated when the voltage feedback reaches a peak and declines.
6. The method of claim 1 , wherein during preheating, voltage applied to the welding electrode is maintained generally constant and current feedback from the electrode is monitored for a decrease.
7. The method of claim 1 , wherein the applied voltage and current are monitored to determine when the welding electrode has reached a resistance, and preheating is then terminated.
8. The method of claim 1 , wherein the applied voltage and current are monitored to determine when the welding electrode has reached a power level, and preheating is then terminated.
9. The method of claim 1 , wherein at least one of the applied current, the applied voltage and the termination of preheating is based upon a type and size of the electrode.
10. A welding method, comprising:
receiving a signal indicative of initiation of welding process;
prior to initiating a welding arc based on the received signal, automatically controlling voltage or current applied to a welding electrode to preheat the electrode to a temperature above an ambient temperature but below a melting point of the welding electrode;
terminating preheating when the electrode reaches a resistance or a power level as determined based upon monitored current and voltage applied to the welding electrode; and
initiating the welding arc in accordance with a welding protocol after terminating preheating of the electrode.
11. The method of claim 10 , wherein termination of preheating is based upon a feedback voltage reaching a threshold.
12. The method of claim 10 , wherein termination of preheating is based upon a feedback current reaching a threshold.
13. The method of claim 10 , wherein termination of preheating is based upon a feedback voltage reaching maximum level and declining.
14. The method of claim 10 , wherein at least one of the applied current, the applied voltage and the termination of preheating is based upon a type and size of the electrode.
15. A welding system, comprising:
a power supply comprising power conversion circuitry and control circuitry configured to cooperate to provide welding current and voltage to a welding electrode;
and
current and voltage monitoring sensors configured to sense current and voltage applied to the welding electrode by the power supply;
wherein the control circuitry is configured to receive a signal for initiation of a welding process and to, prior to initiating a welding arc based on the received signal, control the voltage and current applied to the welding electrode to preheat the welding electrode to a temperature above an ambient temperature but below a melting point of the welding electrode, to monitor the sensed current and voltage to determine a termination of preheating, and to terminate preheating prior to initiating the welding arc in accordance with a welding protocol.
16. The welding system of claim 15 , comprising a welding torch configured provide a signal to the control circuitry to initiate the welding process.
17. The welding system of claim 15 , wherein during preheating, current applied to the welding electrode is maintained generally constant and voltage feedback is monitored for an increase.
18. The welding system of claim 17 , wherein preheating is terminated when the voltage applied to the welding electrode reaches a predetermined threshold value.
19. The welding system of claim 17 , wherein preheating is terminated when the applied voltage reaches a peak and declines.
20. The welding system of claim 15 , wherein during preheating, voltage applied to the welding electrode is maintained generally constant and current is monitored for a decrease.
21. The welding system of claim 15 , wherein the applied voltage and current are monitored to determine when the welding electrode has reached a resistance, and preheating is then terminated.
22. The welding system of claim 15 , wherein the applied voltage and current are monitored to determine when the welding electrode has reached a power level, and preheating is then terminated.
23. A welding method, comprising:
receiving a signal indicative of initiation of welding process;
prior to initiating a welding arc based on the received signal, determining an amount of time that a welding wire has not been under an arc condition;
determining at least one of a preheating time, current, or voltage based on the determined amount of time;
terminating a preheat cycle based on a timer; and
initiating the welding arc in accordance with a welding protocol after the preheat cycle has terminated.